H. P. Friedrichs (AC7ZL) Homepage

Radio Room

If Rigs Could Talk:

An Iraqi Veteran Comes
to the United States

Introduction

While I am as enthusiastic about cutting-edge technology as
any person, I have a special fondness in my heart for
vintage electronic and radio equipment. My reasons vary. In
some cases, vintage equipment exhibits the aesthetics of
elegant, if outdated, design. Sometimes there is beauty in
the attention to detail and care with which the equipment
was fabricated.
Often, my attraction is rooted in wonder as to the history
associated with that gear. Where did it come from? Who
might have owned it? I know I'm not alone in asking such
questions, because I have met antique and "boat anchor"
enthusiasts who will research prior owners of a transmitter
or receiver with the same enthusiasm and vigor that they
would apply to researching their own genealogy. Ah, but if
old rigs could only talk! What might they tell us about
historical people, places, and events?
Recently, I set out to research and restore a piece of
battle-tested communications gear from the first Gulf War,
and these questions lingered in my mind. The radio itself
is a marvelous piece of engineering, but the equipment's
history and how it came into my possession is an
interesting tale in its own rite.

The First
Gulf War

Iraq's relationship with Kuwait has always been strange, if
not strained. While Iraq has never recognized Kuwait's
sovereignty, the two countries were none the less allied
during the Iran-Iraq war of the 1980's. Kuwait even
provided financial resources to fund Iraq's efforts.
Unfortunately, this assistance left Iraq in debt to the
tune of some 14 billion dollars, a significant source of
resentment for Iraq's leader, Saddam Hussein. It was
later alleged that Kuwait was engaging in "slant drilling"
into Iraqi oil fields, building settlements on Iraqi soil,
and devaluing Iraqi oil by exceeding OPEC oil production
quotas. Hussein decided that there was justification for a
military invasion into Kuwait. The annexation of Kuwait, he
reasoned, would resolve these problems, as well as leave
Iraq in control of 20% of the world's oil reserves. So, on
the 2nd of August, 1990, Iraqi forces swarmed the border
into Kuwait.

During their occupation, Iraqi forces are alleged to have terrorized Kuwait's
population with acts of torture, rape, and murder.
Hospitals were gutted, and key infrastructure elements like
desalination plants were destroyed. Communications
equipment was gutted, leaving Kuwait disconnected from the
rest of the world. Oil facilities were blown up and left in
flames. In many cases, anything of value, including items
bolted to the floor, was ripped out and transported back
into Iraq.

Only later would Hussein realize that his
decision to invade Kuwait was a matter of grave
miscalculation.
After the adoption of a series of impotent United Nations
Resolutions, a coalition of 18 countries, headed by the
United States, began the execution of a decisive response.
On January 17th, the pulverization of Iraqi military forces
commenced. Ultimately, more than 1300 aircraft engaged
targets dropping 60,000 tons of explosives. In round
numbers, 840,000 ground troops deployed and maneuvered 8600
tanks, 15,000 armored vehicles, and 7,000 artillery pieces
of various types.
Iraq's air force was rendered irrelevant almost overnight.
In the days that followed, coalition forces destroyed 3700
Iraqi tanks, 2400 armored vehicles, and 2600 artillery
pieces, including 1400 retreating vehicles annihilated on
the infamous "highway of death."

The AMX-10P

Much of Iraq's military hardware was exported to them from
other countries, including the AMX-10P, manufactured by the
French. Introduced in 1973, the AMX-10P is a tracked,
armored, infantry fighting vehicle. A 300 horsepower diesel
engine will drive the 16-ton vehicle to speeds up to 40
miles per hour. It is armed with a 20-mm dual-belt-feed
automatic cannon, and a 7.62-mm coaxial machine gun. The
standard crew consists of 3 persons, with carrying
capability for up to 8 passengers.

It is not difficult to imagine a specific AMX-10P and its
crew, somewhere in the middle of the melee described earlier,
exchanging gunfire with coalition forces. They may have
been launching an assault, or perhaps they were attempting
to retreat. Either way, by the time the shooting had ceased
and the thunder of cluster bombs had receded, the vehicle
in question had been reduced to scrap metal. At that point,
any sign of life would have been limited to the faint
crackle of a VHF transceiver mounted beneath the driver's
seat. Bear this image in mind, as it will become relevant
in just a moment.

Gulf War II

Following the first Gulf war, the United Nations Security
Council issued resolution 687 which declared a formal
ceasefire and prescribed to Iraq the terms of peace. Among
those conditions was the requirement that various types of
weapons systems be dismantled and rendered nonfunctional
and that Iraq must allow inspection teams to verify
compliance.
A decade later, on the 8th of November, 2002, the Security
Council unanimously approved resolution 1441, which
recognized Iraq's failure to comply with the terms of 687.
Resolution 1441 and faulty intelligence about the status of
Iraq's remaining WMDs (weapons of mass destruction) led to
the formation of a new coalition, one whose purpose it was
to disarm Saddam Hussein by force.

On March 20th, 2003, the
United States, the United Kingdom, Australia, South Korea,
Italy and Poland launched an offensive that smashed Iraq's
remaining military and toppled the Saddam Hussein regime
forever.
WMD's or not, the horrific effects of Saddam's
handiwork are felt to this day.

One of the practical considerations of regime change, and
one of the real dangers, is that the vacuum formed by the
removal of a despot may be filled by something far worse.
As we have seen since 2003, managing this vacuum and
helping the Iraqi people to transition back to stable
autonomy is a daunting and resource-intensive task, one
which has demanded the talents and dedication of thousands
of our military people.

Meeting
Sgt M

Several years back, I wrote and published two books. The
first, The Voice of the Crystal, deals with basic radio
principles, problem-solving philosophy, and details on the
construction of radio components from scratch. Projects
include headphones, coils, capacitors, and detectors
fabricated from shoe polish tins, bits of wire, a part of a
cigarette lighter, and other trashcan flotsam. The second
book, Instruments of Amplification, deals with the concept
of amplification. It features projects ranging from
electromechanical amplifiers built from coils and carbon
rods to homebrew vacuum tubes and experimental homebrew
transistors. Many thousands of these books are now in
circulation, and as a result of this modest success, I have
had the good fortune to meet and correspond with people
from around the world.

I first met Sgt M under these circumstances. He contacted
me with some book-related questions, and we began a
pleasant dialog. Sgt M is an intrinsically nice fellow,
more than reason enough to engage him, but it turns out
that his enthusiasm for electronics and radio, in many
ways, parallels my own. Needless to say, we became friends,
and our correspondence continues to this day.

At one point, I received an email in which he described an
opportunity he'd had to visit one of Hussein's junkyards---
the place where damaged and destroyed military hardware,
like the AMX-10P described earlier, was taken to be
scavenged for parts. Sgt M later described his adventure
this way:

"I was working primarily out of an LSA (Logistical Supply
Area) North of Baghdad Iraq. My bread and butter for this
tour in Iraq was implementing and upgrading various types
of communication Systems theater-wide. At least once a
month, I would thumb a ride via rotary wing aircraft to
establish and maintain individual Units' communication
systems in remote areas. All of the Units that I traveled
to fell under our command in theater and most were
National Guard / Reserve components that did not have their
own direct support personnel.

It was on a short routine trip to Al Taji to check up on
and hopefully increase the bandwidth for one of our
Companies that I came across these radios. I enjoyed trips
to Taji for the simple fact that I could always somehow
improve their connectivity in one way or another. The
payback for me was a very nice trailer to sleep in and a
bit of time in the evening to my self for how ever long I
stayed (this was a hot commodity in my book).

It was one late afternoon that I ran into a Company
Commander from one of the Postal Units on Al Taji who
heard I was in the area and had a couple of very important
questions. He wanted to know how to use a PRC-77 radio and
where to find batteries for them. After talking some time
and explaining to him the best I could without actually
having a radio to show him, he brought me to his make-shift
plywood office. In his office, stacked very neatly up
against one of his self-proclaimed architectural master
pieces he called "a wall," there had to have been over 20
PRC-77s, all in great shape. I was very excited hoping that
with my information about getting them up and running I
would in return receive at least one of these radios for
myself. This was not the case, but what he said he would do
for me is take me to an old gulf war bone yard full of
battle-scarred depleted uranium-saturated tanks, boats, and
a wide variety of fighting and troop transporting vehicles.
Of course I was disappointed not getting a radio or two out
of the deal but the trip did sound interesting and in any
case relaxing. Needless to say I think the crusty old
Reserve Postal Unit Commander may have lost a couple of DSN
phone lines before the week was out.

We decided on heading out the following morning right after
sunrise with a couple of field grade officers joining us
that had not yet made it out there. The trip did not take
very long it was maybe a couple miles from the Unit that I
was working on. It was a very impressive sight, row after
row of disabled vehicles of all shapes and sizes. We drove
up and down the rows as I listened to the old men speculate
what type of vehicle we where looking at and what country
would have brought it over here. Finally I was given a
chance to get out and really explore the insides of this
things, most of which where in good shape on the inside
they where just missing every nut and bolt that wasn't
destroyed and may have been worth something.
It was during my exploration of a very strange vehicle that
I ran across something that caught my eye. This track
vehicle had a rear end shaped like a US Army 113 APC
(Armored Personnel Carrier) and a barrel attached that
looked a little smaller then our Bradley Fighting Machines
25MM. I noticed some old radio mounts still bolted down on
a shelf inside and saw where they had been cannibalized at
one time probably from some one just like my self. I
started to dig around the driver's area looking for cables
or anything else that might lead to some sort of treasure.
It was then that something caught my eye that was buried
under a thick silky layer of Iraqi dust, a radio knob.
The radio I uncovered was bolted directly under the
driver's seat and the way it came out seemed to me like it
was an "Oh Sh*t" radio. What I mean by this is it was
capable of being removed from the vehicle very quickly
before they had to abandon it and still maintain some sort
of communications to the mother ship.
I wish I knew what make and model those vehicles where that
I pulled the radios from. The only really big clue that I
had was everything inside was written in French, I suppose
that's about as detailed as I can get. I did a little
research online and discovered a track vehicle that looked
pretty close to what the radios where in, it is called an
AMX-10P."

I studied the photos Sgt M sent with great interest. Imagine
my surprise when he declared his intent to send me one of
his treasures! "My only condition," he said, "is that if
you figure out how to get it working, that you'll help me
with mine."
Sgt M filled out the necessary paperwork to have the radios
declared as "war trophies," and they were shipped to North
Carolina. Not long after that, a large box appeared at my
home in Arizona. I opened it with excitement, and even my
wife stood nearby to see what would emerge from carefully
padded box. The mystery transceiver had arrived!

A First
Glance

Sgt M's package contained two assemblies. The first was a
radio set composed of an olive-green radio chassis, a
snap-on power supply/accessory unit of some type, and a
15-watt RF linear amp attached to the side of the radio
like a sidecar. The second assembly was a green aluminum
brick with rows of BNC connectors on opposite ends. This
appeared to be some kind of bandpass filter.

All of the hardware was muddy, and peppered with gobs of
what appeared to be hardened cement. Since this was, after
all, combat military hardware, I thought it reasonable to
assume that it would tolerate some moisture. I took the
equipment out back and attacked it with the garden hose and
a nylon brush. The "cement," it turns out, was sunbaked
clay, not unlike the caliche found here in the Southwest.
All of the equipment cleaned up nicely.

The transceiver, as received, was composed of three
subassemblies. The first, the transceiver itself (part
number ER95B), a box-like accessory module (part number
BJ231A ) which fastens to the bottom of the receiver, and an RF
power amplifier module (part number AM215A ) which was bolted
to the side of the transceiver in "sidecar" fashion.

The transceiver is fitted with all of the operating
controls and connectors for a headset and antennas. The
controls include two tuning knobs, one of which sets the
MHz portion of the desired frequency, the other which sets
the KHz portion. Frequency is displayed mechanically
through two tiny, round, windows. Selectable frequencies
span the range of 26.000 MHz to 71.950 MHz, with a 50 KHz
spacing. This means that from end to end, the system
provides 920 discrete channels. Since this is a fairly
extensive range of frequencies, the designers broke up this
span into two bands, which are selectable with a front
panel switch.

Additional controls include the obvious, a
volume control, a squelch control, and a multi-position
mode switch. The mode switch turns the radio on, places it
under local or remote control, and allows activation or
deactivation of the squelch.

The antenna terminals, which include a BNC as well as a
threaded well in which to secure a whip antenna, are
located towards the left side of the control panel. At the
right of the panel are two circular connectors, identified
by Sgt M as "U-79" connectors. (Note: The U-79 is a panel
mount connector. The mating connector is called a U-77.)
Obviously, these are connection points for the operator's
headset.

The accessory module is held into place at the bottom of
the transceiver with two spring-loaded suitcase-style
snaps, and links to the transceiver internally with a
captive DB-25 connector. The outside of the accessory
module almost bristles with military-style circular
connectors. The side of the module features connectors for
power, remote control, for control of the external RF amp,
and for interface to what I presume would be an antenna
tuner/matching unit. In addition, there are several
connectors at the bottom of the module for test and other unknown
purposes.

The outboard RF amplifier was attached to the left side of
the transceiver. A short length of coax fed the amp from
the BNC connector on the face of the transceiver. At the
rear of the amp is a short but fat pigtail that links to
the accessory module. This must be the conduit through
which power and control signals are applied to the amp.

Two interesting contradictions are inherent in the radio
I've just described. First, while the radio is clearly of
French origin, and the connectors on the accessory module
are labeled in French, the front panel controls are labeled
in English.
Second, while Sgt M had salvaged this radio from a tracked
vehicle, its overall design said "manpack" to me. After
all, the radio clearly supports the use of a whip, and I
could easily envision the accessory module removed and
replaced with a similar box filled with batteries.

Dead Ends
and Discoveries

The nameplate indicated that the radio had been
manufactured by Thomson CSF. I Googled "Thomson," and
discovered that they are now doing business under the name
"Thales." I found a phone number for the company division
in the United States. I spoke with an engineer and inquired
how I might be able to get my hands on schematics or
service information. He was friendly, though unable to help
me. He indicated that the documents pertaining to the radio
were controlled by Thales in France. He ended our
conversation when he made a peculiar remark, wishing me
"luck" in dealing with the French. Hmm.

Next, I composed a letter to Thales in France. I don't
speak French, so I composed the letter in English and then
used one of the online translation services to convert the
message. It was weeks before I heard anything from them,
and when I finally did, they simply remarked that the radio was
"obsolete" and that they could not help me.

A Google search of "ER-95" yielded little,
so I decided to
change gears. Since the radio was French, it occurred to me
that I should try a search using French words to search with. I initiated
searches using words like "transmetteur" (transmitter)
"récepteur" (receiver) and "militaires" (military). This
path eventually led me to the web site of a French surplus
dealer. I scanned through the photos on the web page with
the hope that I might find an example of my radio. I
eventually stumbled on the image of a set that was
identical to mine, but for minor differences associated
with the shape of the tuning knobs. The caption read:
"TR-PP-13."

Armed with the discovery that the transceiver was known by
nomenclature other than ER-95, I Googled "TR-PP-13." The
resulting links led me to a goldmine of information in the
form of an article entitled, The French/Italian
TR-PP-13/RV-3 (ER-95A) VHF FM Radio. This article,
authored by J. Feyssac and M. McCabe, was featured in the
June 2004 issue of the Vintage and Military Amateur Radio
Society newsletter.
According to Feyssac and McCabe, most of the NATO armies in
the mid 1950's made use of the PRC-10 family of military
radios. Military demands for improvements and the growing
proliferation of transistors led to the development of the
PRC-25 in 1961, and eventually, the PRC-77. France decided
not to adopt the PRC-77, but rather, design her own system.
This decision led directly to the development of the
TR-PP-13, manufactured by Thomson CSF, and the later
production of the RV-3, an Italian variant manufactured
under license by Elmer.

The VMARS article goes into considerable detail about the
design and specifications of the TR-PP-13, including a
description of the how the internal frequency synthesis is
accomplished. In short, I can say that the receiver is a
single-conversion superhet with sensitivity to 0.5uV (18 dB
s/n). Audio output is 5 mW. The transmitter (without the
outboard RF amplifier) produces 1.5 watts (a 5 to 15 km
range). The transceiver contains 46 transistors, and weighs
in around 25 pounds.

As I had initially suspected, the TR-PP-13 was deployed in
at least three different configurations...a manpack, a jeep
radio, and a "tank" version. The tank version, system
TR-VP-213 (Italian RV-4/213/V,) consists of the radio, the
BA-301 power supply (Thomson calls this a
BJ231A) and the RF-AM215 amplifier. This is consistent with
the hardware that Sgt M sent to me.

Getting
the Radio Working

Despite the excellent article by Feyssac and McCabe, I was
still without schematics, and still unable to power up the
radio. I decided that a look inside might offer some
clues. I unsnapped the accessory module from the bottom of
the radio, and then I removed the metric Allen-head bolts
which secured the radio into its case.

Predictably, the interior exhibits high quality
construction. Most of the electronics associated with the
radio is housed in small, silver-plated metal modules that
plug into to the set. Wiring harnesses are neat, short,
tight, bundles. Of course, while this type of construction
makes for a rugged set that is easy to service in the
field, it makes reverse engineering exceptionally
difficult.

Starting with a connector labeled "Alim
24" mounted to the
side of the accessory box, I used my ohmmeter to trace some
of the wiring. I eventually decided that, on the basis of
these measurements, the radio case was a negative ground,
and that three pins on the power connector must receive
power. I removed the RF amp and its cabling from the radio
(figuring I'd work on that part later). Using alligator
leads, I rigged up a current-limited bench supply to
provide 24 volts and switched on the radio. There was
evidence of a current draw. I turned the radio off.

I was curious about a knurled knob on the face of the
transceiver. It was embossed with a curly symbol,
reminiscent of a lamp filament. I presumed it might have
something to do with a pilot or dial light. I unscrewed the
knob, and found an empty lamp socket beneath it. I replaced
the bulb and turned the radio back on. The circular windows
in which the frequency is displayed lit up. So far, so
good.

Next, I had to try to figure out how the headset connector
was wired. Unfortunately, the wiring can't be followed from
the inside of the radio, and without schematics, my only
recourse was trial and error. I powered up the radio and
began probing the connector pins with the terminals of a
2000-ohm high-impedance headphone. My logic was that this
might help me locate the audio output pins, and even if I
crossed something that I should not, momentary contact was
not liable to damage anything. I turned the radio on,
turned the volume all the way up, and the squelch all the
way down. Sure enough, as soon as I touched pins "A" and
"B" I heard the hiss associated with an un-squelched FM
receiver.
I continued probing the connector, and discovered that when
terminals "F" and "H" were shunted, a relay inside the
radio clicked and the audio was silenced. I was sure that I
had found the PTT (push-to-talk) terminals. From that point
on, I connected the radio to my 50 ohm dummy load to
protect the RF finals and to make sure that I would not
unintentionally radiate signals.

A few days later, I discovered Brooke Clarke's website.
Posted there, he shows the pinout for the U-79 connector as
deployed on PRC family radios. I compared this information
to the wiring I had derived through my experimentation, and
found that it matched. This suggested to me that the
microphone terminals must be pins "C" and "E." I also
learned that the PRC family radios utilized carbon
microphones, which implied that this radio would require a
carbon mike, as well.

I rummaged through my junk box and retrieved an old,
standard, telephone handset. These contain a dynamic
speaker and a carbon microphone. I gutted the handset and
drilled a hole on the handle, near the earpiece, in which
to install a momentary-contact PTT switch. I rewired whole
thing, fabricated a nice cable, and then terminated that
cable with a U-77 connector purchased from Fair Radio
Sales. Before finalizing assembly, I gave the handset two
or three coats of military-olive-green paint so that it
would match the radio.

I made duplicates of my homebrew handset and power cabling,
and sent them off with a power supply to Sgt M, along with
details of what I'd learned. Last I'd heard, his transceiver fired up and worked
fine.

And the
RF Amp?

The short story on the RF amplifier is this: Try as I
might, I could not get the amplifier to key up. I probed
the connector that feeds the amp, but failed to identify
any of the signals. I opened the amplifier to study its
innards, but nothing there suggested what I must do to get
it working.
My guess is that something must be strapped on one of the
radio's other connectors to enable the operation of the RF
power amplifier. Given the relative complexity of the
hardware I'm dealing with, combined with the nature of its
construction, it is unlikely that I'll get the amp
functioning without additional technical documentation.
If any of my readers should have an idea as to where I
might obtain schematics for this radio, I would be very
interested in hearing about it.

So What's
the Point?

As far as I can tell, this rig works great. The receiver
seems sensitive, and the audio quality of received signals
seems pretty good. Even with a makeshift antenna, I can
pick up audio from television channels 2 (59.75 MHz) and 4
(71.75 MHz). I have transmitted into my dummy load numerous
times, and when my handheld scanner is brought near, the
audio quality of the signal emitted by the radio is
remarkably clear and crisp.
It might be fun to rig up an antenna and try out this radio
on the 6 meter band (50 MHz to 54 MHz). The 50 KHz channel
resolution and 20 KHz channel width limits one's agility,
but looking at the band plan, there are several places I
could probably operate. Sgt M send me an email wondering if
these radios could be utilized with PSK-31. I don't see why
not, assuming a suitable interface was constructed.

A few months back, I penned an article in which I described
my restoration of an old BC-348. By far, most readers
applauded my efforts, though at least one asked why I would
bother. He said, "It's just an old obsolete radio with a
lot of hours of work to make it function worse that a $20
Chinese SW radio. So why would we do this?"
No doubt this person and others like him would ask the same
question about my TR-VP-213. After all, it too is old,
obsolete, and of limited value on the ham bands.

The
question is a fair one, though I submit that it is only
likely to be asked by those who do not understand that a
journey can be more important than the destination.
As I reflect on my efforts to research and get Sgt M's
radio functional, I note that I have learned some history,
and some politics. I've corresponded with military radio
enthusiasts in the UK, and I've learned a few words of
French. I learned some new things about military radios,
their ancestry, operation, design, and construction. Most
importantly, a mutual appreciation of radio and electronics
created the opportunity for, and solidified, my friendship
with a serviceman on the opposite side of the globe. If
these benefits are not representative of the best face of
ham radio, I'm sure I don't know what is.

As for the radio and its history, one can only imagine
where it has been and what it has seen in its travels--
from France to the deserts of Iraq... from the deserts of
Iraq to brutal combat....from combat to a peaceful
boneyard... from the boneyard to North Carolina and then
finally to Tucson, Arizona in the United States of America.
Oh, if only rigs could talk!

A Brief
Editorial Comment

The U.S.A.'s actions in Iraq and elsewhere around the world
have been the source of friction between our nation and
others, and between the members of our increasingly
polarized population. The intent of this editorial is not
to advocate any particular position, but simply to suggest
that you reflect, from time to time, on the extraordinary
sacrifices made by the members of our Army, Navy, Air Force,
Marines, and Coast Guard.

If you fly a flag at home or display a "Support the Troops"
sticker on your bumper, that's well and good, but I would
urge you to take the next step. There are thousands of
servicemen overseas who would appreciate a friendly letter
from someone back home. Better yet, consider sending a
"care" package filled with socks, candy, instant beverage
mixes, magazines or similar items. What better way to say
"Thank you?"

"What should I send?" you ask. "To whom do I send it?"
Start by visiting www.anysoldier.com

Web Article
Update: New Information and New Functionality!

After preparing and posting the article above, I continued
tinkering with the radio in an effort to get the RF amp running.
The breakthrough finally came after I was able to establish contact
with Murray McCabe, one of the authors of the VMARS
article I described earlier. Murray has accumulated considerable
information on the TR-VP-13, including schematics and other critical
information. This data is available on CDROM for a very reasonable
charge, and I was more than happy to purchase a copy. With this
new information, I revised the power harness I had created earlier,
and then created a simple shunt or "jumper" for one of
the accessory connectors to enable full RF power when I want
it. Let me summarize what needs to be done here.

To build the appropriate power cable, one
needs a military circular connector with a part number of PT06A-10-6S
(or an equivalent.) Cut, strip, and tin six wires for the power
harness, and solder one to each of the six connector terminals.
The three wires from pins (B), (C), and (D) are joined together
and become the positive (+) 24-volt connection to the radio. The
three wires from pins (A), (E), and (F) are joined together and
become the negative (-) 24-volt connection to the radio. The power
harness you've created is attached to the connector labeled "ALIM
24 V." I no longer connect any wiring to the radio housing.

To enable the RF amplifer, one needs to connect
pin (E) to pin (G) on the connector marked "TELECOM."
For me, this was initially problematic as I was unable to find a
mating plug for that connector. Allow me to explain:

At first glance, it appears that the "TELECOM,"
"ACCORD ANT" and "AMPLI HF" connectors are all
the same-- they are, in terms of their outer shells. Where they
differ is in a feature called "keying." The pin array
in each one has been "keyed" differently, that is to say,
the pin set in each connector has been rotated to a different
angle. This prevents the cables from being attached to the wrong
connector, even though they may share similar shells.

Digging through my junkbox, I was able to
find several connectors that would mate with the "ACCORD ANT."
These were plugs with the part number PT06A-12-8P(SR). I was never able
to find a plug that would mate with the "TELECOM" connector.
I guess the connector keying associated with the "TELECOM"
port must be one of the more rare variants.

To work around this, I fashioned a jumper
composed of an inch of wire with a gold connector pin soldered on
each end. The jumper was installed between pins (E) and (G) on the
"TELECOM" connector. To protect the jumper, I took a PT06A-12-8P
and drilled out its center, leaving only the hollow shell. This
will
fit the TELECOM connector and acts as a tough cover for the jumper.

I may be stating the obvious, but here are
a few additional points to keep in mind: The TR-VP-13 must be connected
to the amplifier with a BNC patch cord running between the front
of the radio and the front of the amplifier. A 50-ohm antenna is
attached to the BNC connector at the rear of the amplifier. Also,
at the rear of the amplifier, is a short, thick, cable that links
the amp to the connector on the radio marked "AMPLI HF."
This cable must be in place for the amplifier to function. Finally,
The toggle switch on the front of the amplifier allows you to select
the transmit power level.

Useful
and Interesting Links

I asked Charlie, my assistant,
to prepare a brief list of URLs that might be of interest to those
seeking additional information on the topic above. This is what
he came up with: